Traditional design techniques and trends within the aircraft industry have led designers to produce aircraft with profiles which use double curvature panels to describe their external lines. The use of such complicated external shapes in the design of both military and civil aircraft has resulted in the need for elaborate and therefore expensive tooling used in both the manufacture of detailed parts and final assembly.
Within the military aircraft industry, traditional design drivers have been for operational performance improvements, however, more recently a switch in emphasis has been towards providing an effective balance between performance improvement and life cycle cost reductions. This new direction in aircraft design has enabled engineers to study the possibilities of eliminating the familiar double curvature airframes and additionally has provided for research into possible new methods of manufacture and assembly for faceted structures.
One of the prime cost driving elements associated with the final assembly of modern combat aircraft is that relating to the installation of aircraft systems. The integration and final assembly of environmental control systems (ECS), engine systems, fuel systems, life support systems and avionics is arguably the most time consuming and expensive area of final assembly and therefore much research has been conducted into the possible reduction in complexity of such systems in combination with the introduction of faceted fuselage outer profiles.
Conventional methods of aircraft manufacture have required a vast range of specialized machining processes to cope with the assembly of double curvature structure and panelling along with the requirements for engineering practices such as shimming or adjustment, contour cutting, drilling and adjustment of details during the assembly phase of aircraft production. A further product of double curvature fuselage designs is the requirement for handed components, and in most cases the use of a wide range of fasteners to cater for the interface requirements of such complex shaped designs.
Our invention provides a method of manufacture for aircraft which substantially reduces the need for high manpower requirements on aircraft final assembly by the simplification of both the manufacturing and integration processes related to both structure and aircraft systems.